Cleaning machine for shuttering boards used for concrete formwork



Nov. 12, 1963 R. 1.. SAINIO 3,110,050

- CLEANING MACHINE FOR SHUTTERING BOARDS USED FOR CONCRETE FORMWORK Filed Feb. 9, 1962 United States Patent 3,119,059 CLEANING MACHINE FGR SHEJTTERING EQARDS USED FOR CONCRETE FGRMWURK Rainer Lennart Fsainio, (Bhsasenlratu 1, Lappeenranta, Finland Filed Feb. 9, 1962, Ser. No. 172,135 13 Claims. (Cl. 15-93} This invention relates to a cleaning machine intended for cleaning shuttering boards used for concrete formwork and similar construction materials. Said machine is provided with a cutting device which is moved to-andfro at right angles to the Work by means of a vibrator.

It is well known that there is always a certain amount of concrete which sticks to shuttering boards used for formwork. In most cases this concrete prevents the reuse of the boards for formwork. Such boards are heavy and difiicult to handle.

The aforesaid difiiculties have often resulted in used forrnwork boards being sold for firewood at the work site at a very low price. However, this involves considerable waste, since the boards are completely undamaged except for the adhering concrete.

Attempts have been made to clean used formwork boards by using hand tools, but cleaning costs are so high that the method is uneconomical.

Machines have been built with a chopping cutter held approximatively at right angles to the board. However, these machines were not able to clean boards sufficiently to permit re-use.

It is an object of the invention to provide a machine which will rapidly and efiectively clean adherent concrete from boards used for formwork.

The aforesaid invention is characterized in that a cutting device is provided with a spring loaded device which imparts a to-and-fro motion in the plane of the board to the cutter.

The appended drawing illustrates an embodiment according to the invention wherein FIG. 1 shows a machine according to the invention in a side sectional view taken along line II in FIG. 2.

FIG. 2 shows a section taken along line llll in FIG. 1.

FIG. 3 shows a section taken along line llllll in FIG. 1.

FIG. 4 shows a section taken along line IVIV in FIG. 1.

Numerals 1 and 2 designate angle iron cross-braces which support the machine. Holes 3' are provided in the braces to attach the machine to a suitable support. Between cross-braces 1 and 2, there are longitudinal braces 4 and 5 welded in place. At each end of the machine, there is mounted conveyor rollers 6 and 7 mounted in bearings. The broken lines appearing above rollers 6 and 7 represent the board to be cleaned which moves from left to right (FIGS. 1 and 2). Along the longitudinal braces 4 and 5, four angle iron braces 8, 9, 1t? and 11 have been welded. On braces 8, 9, 1t) and 11 longitudinal paired angle irons 12, 13 and 14, 15 have been mounted. Paired angle irons 12, 13 and 14, 15 act as guides, defining the path along which the board slides.

At the feed end of the machine vertical braces 16 and 17 are bolted to the longitudinal braces '4 and 5. Shaft 19 is supported in bearings welded to vertical braces "ice L5 and 17. Rocker arms 2t) and 21 are attached at opposite ends of shaft 19. The ends of rocker arms 20 and 21 are joined by shaft 22. At shaft 22 a vertically operating vibrator motor 23 is mounted on rocker arms 29 and 21. Rocker arm 21 extends beyond shaft 19, thus forming a two-armed lever 21, 28. The vertical position of the vibrator 23 can be adjusted with lever 21, 28.

A tube 24 connected to pivot arms 25, 26 surrounds shaft 22 which is supported in hearings to join rocker arms 2% and 21 to each other. Pivot arms 25 and 26 are fixed to both ends of tube 24 and they are joined by means of rod 27 to which is screwed cutter 29. Discs 32 and 33 are attached to the rod ends 30 and 31 extending from rod 27. Several holes are provided in discs 32 and 33 in which one end of tension springs 34 and 35 are accommodated. The other ends of springs 34 and 35 are accommodated in one of several holes in the rocker arms 2% and 21 which support vibrator 23. When under tension, springs 34 and 35 tend to reduce the angle formed by arms 20, 21 and 25, 26. If the aforesaid springs are not under tension they tend to prevent any reduction in the aforesaid angle. This is illustrated in the drawing.

Beneath the cutter 2) there is supported on the longitudinal braces 4 and 5 a back cutter device. This back cutter device comprises two angle irons 36 and 37 extending parallel with the longitudinal braces and four back cutters 38 extending parallel with cutter 29 and Welded to angle irons 36 and 37. The back cutter device rests free- 1y on longitudinal braces 4 and 5 and can be moved several millimeters in a longitudinal direction between angle irons 9' and N.

In front of cutter 29 and the back cutter device a member 39, constituted by a bent iron strip is screwed in place. Two vertical shafts 40 and 41 are mounted at the top of member 39. At the lower ends of shafts 4t} and 41, rollers 42 and 4-3 are carried in bearings. When rollers 42 and 43 are positioned freely a one-inch board can pass edge-wise between them. The purpose of the rollers is to support the board.

Boards are fed from left to right through the machine (FIGS. 1 and 2). When the leading edge of the board is beneath cutter 29, arm 28 is pressed down until the board just tits in the space between cutter 29* and the back cutter device. Then vibrator motor 23 is started, operating at 3000 vibrations per minute, for example. Rocker arms 2% and 21 and thus pivot arms 25, 26 and cutter 2 begin to vibrate vertically. The effective power of the vibrating cutter is regulated with the two-armed lever 20*, 28. When arm 28 is raised springs 34 and 35 are subjected to increased tension and they tend to diminish the angle created by rocker arms 29, 21 and pivot arms 25, 26 and press the vibrating cutter 29 more strongly against the board that is being cleaned. When the power of the vibrations acts downward, cutter 29 strikes the board. When cutter 29 encounters an obstacle the angle created by rocker arms 20, 21 and pivot arms 25, 26 increases somewhat and cutter 29 moves a small distance in the feed direction of the board, carrying the board with it. When the vibrating power acts upwards cutter 29 does not come free of the board in exactly the same instant, but pulls it in the opposite direction to the teed as a result of the action of springs 34- and 35. It is obvious, however, that the horizontal motion of the cutter 29 in the direction of feed is more powerful than its horizontal motion in the direction opposite to the feed. Thus cutter Z9 automatically feeds the board forward.

It is evident from the previous paragraph that the cleaning action of cutter 2% is based both on its vertical hacking motion and on its horizontal scraping motion.

The back side of the board is cleaned by the action of the back cutters 38. These act on the board with an equal and opposite reaction to the cutter 29 and at the same instant as cutter 2.9. A scraping motion occurs partly because the board is always moving the feed direction relative to the back critters and partly because the back cutter device is caused to move back and forth through the few millimeters of free space between angle irons 9 and it This latter movement results from vibrations set up by the impact of cutter 2%.

When the two opposite sides of the board are thus cleaned, a new board is fed into the machine without shutting down the vibrator.

The edges of the boards are cleaned by feeding them in edgewise. Two supporting rollers 42 and 43 have been provided to hold edgewise fed boards upright. Thin boards are fed between these rollers. Thick boards need not be fed through rollers 42, 43 since they remain in an upright position without special assistance.

The working edges of the cutter 29 and the back cutters 38 are blunt so that they will not damage the surface of the wood. The working edges of cutter 29 and back cutters 38 are exposed to heavy wear. For this reason it is desirable to use hardened metal for the cutters, or to provide cutter 29 with hard longitudinal facing strips welded together.

One of the advantages of the aforesaid inventions include the use of a single drive motor performing a variety of functions. Motor 23 provides the to-and-fro motion of cutter 29 at right angles to the board surface and the to-and-fro motion of cutter 29 in the same plane as the board surface. These motions clean the upper surface of the board. The back or bottom surface of the board is simultaneously cleaned by back cutters 38 as a result of motion imparted by motor 23. Moreover, the feed of the board results from the action of the motor.

This description and the appended drawings are only intended to illustrate the concept of the invention. The actual design and construction versions used in practice can vary widely within the limits of the following claims. This fact is particularly applicable to the device used to furnish to and fro motion along the board. Said device tends to diminish the angle formed by the rocker arms 20, 21 and the pivot arms 25, 26. Such a device can comprise Springs like those in the version described herein. Numerous other arrangements are readily apparent. A very simple version could comprise a cutter 29 heavy enough to provide a torsional force acting on pivot arms 25, 26 sufi'iciently strong that it would tend to diminish the aforesaid angle.

I claim:

1. Apparatus for cleaning material from a fiat board, said apparatus comprising: a cutter adapted for cleaning the board, a pivot arm supporting said cutter, a rocker arm, means pivotally connecting said rocker arm and pivot arm together for pivotal movement about an axis, vibrating means supported on said rocker arm for exerting a vibrating force thereon to cause vibratory movement of said axis and relative pivotal movement between said rocker arm and pivot arm and elastic means operatively associated with said rocker arm and pivot arm and weaker than the vibrating means for resisting relative pivotal movement between said rocker arm and pivot arm for vibration in at least one direction.

2. Apparatus for cleaning material from a fiat board, said apparatus comprising: a cutter adapted for cleaning the board, a pivot arm supporting said cutter, a rocker arm, means connecting said rocker arm and pivot arm together with an angle formed therebetween for pivotal movement about an axis, vibrating means supported on said rocker arm at a location above said axis to exert vibratory motion along a line intersecting said axis, and

elastic means weaker than said vibrating means and operatively connecting the rocker arm and pivot arm together and effective to cause vibratory pivotal movement of the rocker arm and pivot arm in response to vibratory movement of the vibrating means whereby said cutter undergoes vibratory movement in two directions.

3. Apparatus for cleaning material from a flat board, said apparatus comprising: a cutter adapted for cleaning the board, a pivot arm supporting said cutter, a rocker arm, means connecting said rocker arm and pivot arm together with an angle formed therebetween for pivotal movement about an axis, vibrating means supported on said rocker arm at a location above said axis to exert vibratory motion along a line intersecting said axis, and elastic means weaker than said vibrating means and connecting the rocker arm and pivot arm together for resisting relative pivotal movement therebetween which increases the angle formed therebetween, said elastic means being efiective to resist increasing of said angle between said arms during vibratory movement in one direction and to cause relative movement between said arms to reduce said angle therebetween during vibratory movement in the other direction, whereby said cutter undergoes vibratory movement in two different directions.

4. Apparatus for cleaning material from a fiat board, said apparatus comprising: a frame for guidably supporting a board for movement, a cutter adapted for cleaning the board and for concurrently advancing the same in said frame, a pivot arm supporting the cutter, a rocker arm pivotally supported from the frame, means pivotally connecting the rocker arm and pivot arm together in V shaped arrangement with a determinable angle formed therebetween with the cutter in contact with the board, vibratory means supported on said rocker arm for exerting vibratory movement thereon to in turn cause pivotal and translational movement of said pivot arm which in turn causes vibratory movement of said cutter and a spring operatively connected between said rocker arm and pivot arm to resist pivotal movement between said arms which acts to increase said angle, said spring having a strength to exert ,a force on said pivot arm which is less than that caused by vibration of the vibrating means such that said cutter is caused to vibrate along said board in response to the vibrating means.

5. Apparatus as claimed in claim 4, wherein said vibratory means is supported on said rocker arm to exert vibratory forces thereon in a direction substantially normal to the board, said pivot arm and cutter therewith moving in vibratory fashion normal to said board in response to the movement caused by said vibratory means, said spring being effective in combination with said arms and said vibratory means to cause vibratory movement of the cutter along said board, the latter movement being sufiicient to advance the board in said frame.

6. Apparatus as claimed in claim 4 comprising second rocker arms and pivot arms supported symmetrically with respect to the first said arms relative to the frame.

7. Apparatus as claimed .in claim 6, wherein one of said rocker arms is a two-armed lever including a handle remote from the corresponding pivot arm and by virtue of which the two-armed lever can be swung to alter the distance between the vibratory means and the board.

8. Apparatus as claimed in claim 4 comprising a blunt edge portion on said cutter adapted for contacting the board.

9. Apparatus as claimed in claim 4 comprising hard longitudinal welded facing strips on said cutter.

19. Apparatus as claimed in claim 4 comprising a back cutter supported in said frame for cleaning a face of the board opposite that contacted by the cutter, said back cutter being operative while the cutter cleans the associated face of the board.

11. Apparatus as claimed in claim 10, wherein the back cutter device comprises a plurality of edgeWise-positioned back cutters.

12. Apparatus as claimed in claim 11 comprising a pair of angle irons, the edge-Wise positioned back cutters being attached to the angle irons, said angle irons and the back cutters therewith being movably supported in the frame to allow to and fro movement of the back cutters along the board.

13. Apparatus as claimed in claim 4 comprising two 10 References Cited in the file of this patent UNITED STATES PATENTS Melgers Jan. 30, Moore May 5, Beals Nov. 22,

FOREIGN PATENTS Switzerland Dec. 1, Germany Nov. 1, Germany Jan. 5, 

1. APPARATUS FOR CLEANING MATERIAL FROM A FLAT BOARD, SAID APPARATUS COMPRISING: A CUTTER ADAPTED FOR CLEANING THE BOARD, A PIVOT ARM SUPPORTING SAID CUTTER, A ROCKER ARM, MEANS PIVOTALLY CONNECTING SAID ROCKER ARM AND PIVOT ARM TOGETHER FOR PIVOTAL MOVEMENT ABOUT AN AXIS, VIBRATING MEANS SUPPORTED ON SAID ROCKER ARM FOR EXERTING A VIBRATING FORCE THEREON TO CAUSE VIBRATORY MOVE- 